Recycling:Reduce , Reuse and Recycle

Biomaterials are gaining importance as inexpensive adsorbents for removing pollutants, especially heavy metals, from aqueous solutions. Cadmium has been one of the major pollutants in the waters of small foundries and is often released before effective treatment. This paper proposes an inexpensive adsorption based removal of Cd (II) for these foundries using Maize Corn Cob (MCC) as an adsorbent. MCC is an abundant agricultural waste in most parts of India and easily available at very low prices. The dried raw MCC was pulverized and was investigated for its adsorption properties and tested for the removal of Cd (II) from aqueous solutions using different sets of experimental variables. Adsorption of Cd (II) on MCC was found to be dependent on contact time, pH, adsorbent dosage and initial concentration of metal ion (adsorbate). Maximum adsorption occurred at pH 6.0. Among the different sets of experimentation, maximum adsorption was found with an adsorbent particle

size of 0.21mm and the pH of the aqueous solution at 6.0 with Cd (II) concentration of 200mg/l. 200mg of Maize corn cob has the potential to reduce Cd (II) concentration to 1mg from 50ml aqueous solution containing 10mg of Cd (II) with a contact time of 70 minutes. The results of the study reveal that Maize Corn Cob (MCC) can be effectively used for Cd (II) removal in the foundry effluent waters, by optimizing the technique in the field trials.